FIGURE 5.

UBD KD does not affect IRE1 endonuclease activity in IL-1β + IFN-γ-treated rodent and human beta cells. INS-1E cells (A–C) and EndoC-βH1 cells (D and E) were transfected with siControl (siC) or two different siRNAs targeting rat UBD (siU2 and siU3, A–C) or human UBD (si-hU1 and si-hU2, D and E). 48 h later, cells were left untreated or treated with IL-1β + IFN-γ (IL+IFN) for 24 h (A–E). The expression levels of Ubd (A and D), Xbp1s (B and E), and Ins-2 (C) were assessed by RT-PCR and normalized by the housekeeping gene Gapdh (A–C) and β-actin (D and E). The results are represented as points that indicate single experiments plus the average and the S.E. (A–C) or as a box plot indicating lower quartile, median, and higher quartile, with whiskers representing the range of the remaining data points (D and E). *, p < 0.05; **, p < 0.01; and ***, p < 0.001 IL + IFN versus siC; #, p < 0.05, and ##, p < 0.01 as indicated by bars; one-way ANOVA followed by Student's paired t test with Bonferroni correction. Data shown are mean ± S.E. of 3–5 independent experiments.